1. Field of the Invention
The present invention pertains to a medical ventilator and, more particularly, to redistributing heat produced during operation of the medical ventilator.
2. Description of Related Art
Heretofore, medical ventilators included a pressure generator encapsulated in a suitable noise suppression material, such as foam, to muffle noise produced by the pressure generator during operation. While encapsulating the pressure generator in foam has the desired effect of muffling noise produced by the pressure generator, the foam also acts as an insulator that traps in the pressure generator heat produced thereby during operation. Because the pressure generator is utilized to increase the pressure of gas provided to a patient, the heat trapped in the pressure generator undesirably increases the temperature of the pressurized gas provided to the patient. Moreover, the trapped heat increases the operating temperature of the pressure generator thereby decreasing its efficiency.
Medical ventilators often include a bacteria filter for capturing bacteria exhaled by a patient using the medical ventilator. For effective operation, the bacteria filter requires heating in excess of ambient temperature. Heretofore, heating of the bacteria filter was accomplished by a resistive heating element placed in close proximity to the bacteria filter. This resistive heating element receives power during operation of the medical ventilator and converts the power into heat, which is transferred to the bacteria filter to increase its temperature to an effective operating temperature range. A suitable temperature control system can also be provided for monitoring the temperature of the bacteria filter and for controlling the application of electrical power to the resistive heating element in order to maintain the operating temperature of the bacteria filter in its effective operating temperature range.
While useful for heating a bacteria filter to its effective, or optimal, operating temperature range, the resistive heating element increases the temperature of the bacteria filter at the expense of the use of additional power by the medical ventilator. However, if an alternative source of heat were available, it would be desirable to either eliminate the resistive heating element as part of the medical ventilator or reduce the use of the resistive heating element for heating the bacteria filter.